(Lego WeDo crane from the WeDo Resource Set. After building the crane, my kids immediately suspended Max. Mia stands atop the crane.)

In Part 1, I gave a quick overview of the pros and cons of the Lego WeDo system, and described Lego’s recent addition, the WeDo Resource Set. In Part 2, I look for more things that can be done with WeDo, first by going in search of the WeDo user-community, and then using MIT’s Scratch to control WeDo.

What WeDo Community?

It has been about four years since Lego began selling WeDo, and where Mindstorms spawned innumerable books, blogs, and videos of amazing contraptions, WeDo remains one of Lego’s best-kept secrets. One of the factors preventing WeDo from going mainstream is certainly price, but just as important is the fact that this is a toy that works best as a lightly moderated activity. Just how big is the market of kids with parents who like to work together solving technical challenges? Quite frankly, the GeekDad and GeekMom community may be the prime market for WeDo outside of elementary schools and homeschoolers.

So what is out there? On the book front, I found just one: Classroom Activities for the Busy Teacher, WeDo and Animal Sets, Ex... (2011) by Damien Kee and Fay Rhodes. The book includes four designs: scuba diver, tropical fish, manta ray, and sea turtle. 

I have not found any web communities that focus solely on WeDo. The richest source, for now, is YouTube. Most of the WeDo videos you will find there are the core Lego builds. There are a small number of original builds, however. Here are a few that caught my eye:

• This first one is a drawbridge from Italy, or Ponte Levatoio. The model appears to be voice activated and is a very good approximation of the real thing. Note how the creator has closely integrated WeDo into a mini-figure scale play scene.
• This second model is of an oscillating fan from Taiwan. It is something that could have been rendered without WeDo but it is a nifty design nonetheless.
• This next model is my favorite, partly because of the design of the rocket launch pad, but also the young engineer’s explanation of how it all works. His parents admit to some help in the comments section, but that is, I think, a good approach to WeDo. Quite frankly, when I see kids do this, I just about start crying. The video also gives you a quick glance at the model’s programming.
• My last selection is much more technically sophisticated, but it comes from an adult so we have to handicap it. Youtuber "theCliffBar" has built a line-follower. The challenge is creating a design that only uses a single WeDo USB hub. CliffBar chose to drive two motors off one side of the hub, and a motion/distance sensor off the other. With a special transmission and an iterative forward, backward motion, the robot simultaneously searches for the line and steers itself.

This last video begs the question of what can and can’t be accomplished with WeDo’s software and hardware. The main constraint is in the USB hub, which is limited to two I/O connections (though as seen in the line follower, you can gang two motors on one I/O). If you have more WeDo sets handy, you can run up to three hubs from the same program for a total of six I/O ports. This works for a classroom, but is prohibitively expensive at home (the USB hubs cost $44.95 each).

On the software side, the limitations of the WeDo program are significant, but remember, the whole point of WeDo is to remove complexity, to create an environment that kids in early elementary school can own. For kids that need or want to do more, however, there is MIT’s Scratch.

Scratch and WeDo

I hope you’ve heard of Scratch. If not, check it out, because it is a free, cross-platform programming environment for kids created by the brilliant folks at MIT’s Media Labs. And if you don’t know already, these are the same individuals that have worked with Lego in developing Mindstorms and WeDo.

Scratch does not require any extra I/O. As a stand alone program, kids can use it to control the actions, looks, and sounds of animated objects called Sprites. With WeDo or the PicoBoard, these Sprites can be virtual counterparts to action that is happening in the physical world. You can also choose to ignore the Sprites if you just want to focus on robotic control.

Scratch is a graphical programming environment, but where Lego uses simple images to convey function, Scratch’s programming blocks are labeled with commands and simple mathematical operators. This is a good deal more complex than WeDo, but we get real if/then statements and more sophisticated algorithms. Further, Scratch provides numerical feedback from the distance/motion sensor. MIT offers a set of basic tutorials on integrating Scratch with WeDo.

Okay, enough talk. Here are two of my own videos. The first is the car build from the WeDo Resource Kit using Lego’s WeDo software and the provided sample code.

Here is a screenshot of the WeDo program I used:

The second is the same car using a simple Scratch program.

And here is a screenshot of the Scratch program:

In spite of the cost of WeDo, I still would not skip purchasing the official WeDo software. It is simply more inviting for children, though I hope my own kids will eventually get hooked on Scratch.

Until next time, I’m WeDone. Thanks.